A conventional inflator for inflating an inflatable vehicle occupant protection device includes a container having a storage chamber. Inflation fluid under pressure is stored in the storage chamber. An igniter assembly is associated with the container and is actuatable for heating the inflation fluid in the storage chamber to increase the fluid pressure in the storage chamber. The increased fluid pressure ruptures a burst disk. The ruptured burst disk defines an outlet opening through which the inflation fluid flows.
U.S. Pat. No. 5,529,333 describes an inflator for inflating an air bag that includes a container that defines a storage chamber. The container has an opening that leads to the storage chamber. A plug member is received in the opening of the container and closes the opening of the container. Two passages extend through the plug member. A first passage through the plug member enables inflation fluid to flow from the storage chamber toward an air bag. A wall portion of the plug member closes the first passage. The wall portion of the plug member includes a break away center. An actuator is actuatable for opening the break away center of the wall portion of the plug member to form an outlet opening through which inflation fluid flows. A second passage through the plug member is provided for filling the storage chamber with inflation fluid. A ball is located in the second passage for preventing inflation fluid from flowing out of the storage chamber of the container through the second passage of the plug member.